1. Field of the Invention
This invention relates to improvements to peripherally inserted catheters. In particular, the invention relates to a method and apparatus for preventing damage to the catheter by a clamp used to prevent flow through a soft tube, which exits from a patient""s limb.
2. Description of the Prior Art
Peripherally Inserted Catheters (called PICCs), like other types of intravenous catheters, are inserted through a vein in a patient""s arm. The catheters often remain in place throughout the course of the patient""s treatment and therapy.
A PICC catheter includes a long insertion tube 14, which is inserted into a specific vein at an intervention point near the bend of the patient""s arm FIG. 1 of the drawings shows a prior art PICC 10 with an exterior soft tube 12 which communicates with the insertion tube 14 at a surgical tag device 16 which is stitched to the patient""s arm at the insertion point. A soft ferule 18 covers the end of the exterior soft tube. The ferule 18 is a sleeve, which surrounds the exterior soft tube and includes a small diameter tube therein, which runs between an injection site device 20 at the end of the catheter and the exterior soft tube 18. A clamp 22 is provided about the exterior soft tube 12 to prevent fluid flow through the catheter 10 when medication is not being inserted into the catheter 10 or blood is not being taken from the catheter 10.
FIG. 2 illustrates a PICC inserted into a vein at an injection point of the patient. While not illustrated, certain catheters have two exterior soft tubes, which exit in a xe2x80x9cYxe2x80x9d shape. One exterior soft tube is used to inject medication; the other to withdraw blood from the patient.
A problem exists with the prior art PICC of FIG. 1 in that the clamp 22 may ride or xe2x80x9ccreepxe2x80x9d along the soft exterior tube 12 toward the larger diameter soft ferule 18 which forms a sleeve about the end of the exterior soft tube (as shown in FIG. 3). When the clamp 22 is engaged about the soft ferule 18 and the tube inside it, the clamp pinches or crimps the tube within the ferule or the end of the exterior soft tube at pinch point 24 with a high probability of permanently deforming or collapsing or even severing the soft tube or the tube within the ferule. In that situation, bacteria are provided with a path into the interior of the soft tube 12 and directly into the patient""s body. As illustrated in FIG. 2, a bacteria path is provided directly into the patient""s heart, thereby creating an exceptionally dangerous situation.
3. Object of the Invention
A primary object of the invention is to provide an improved PICC where its exterior soft tube clamp is prevented from sliding from the exterior soft tube onto the larger diameter ferule, thereby preventing possible permanent deformation, collapse or severing of the exterior soft tube.
The object identified above is incorporated in an improved PICC where its soft ferule includes a xe2x80x9cball-likexe2x80x9d structure between the soft exterior tube and the soft ferule. The ball-like arrangement prevents the clamp from sliding from the exterior soft tube onto the soft ferule.